DE202010015439U1 - Rotary pump and housing half shell for selbige - Google Patents

Abstract

Rotary piston pump for conveying a fluid medium containing solids, with an inlet and an outlet respectively for the medium to be conveyed, with a pump housing (1) and two in the pump housing (1) arranged rotary piston (7) with interlocking rotary lobes, characterized in that Pump housing (1) has two mutually opposite housing half-shells (3) which close the pump housing (1) fluid-tight and that the housing half-shells (3) are double-walled.

Description

The invention relates to a rotary lobe pump for conveying a fluid medium containing solids, with an inlet and an outlet respectively for the medium to be conveyed, with a pump housing and two rotors arranged in the pump housing with intermeshing rotary lobes. Preferably, the two shafts may be coupled together by a transmission disposed in a transmission housing.

The invention further relates to a housing for a rotary pump for conveying a fluid medium containing solids.

Rotary lobe pumps of the aforementioned type are used for conveying any liquids, but in particular also for conveying sludge, sewage, dirty water, brackish water, thick matter, bilge water, faeces, liquid manure, chemicals or animal feed. Rotary pumps of the type mentioned are, for example, from the DE 10 2007 054 544 A1 and the EP 1 624 189 B1 the applicant and from the DE 10 2005 017 575 A1 and the WO 2007/026 109 A1 known and serve to promote a fluid medium containing solids.

The medium to be delivered passes via an inlet opening arranged on the pump housing into the interior of the pump housing, is conveyed there by the intermeshing rotary lobe wings of two driven rotary lobes in the direction of an outlet opening arranged on the pump housing and leaves the interior of the pump housing again through the outlet opening. Each of the two rotary pistons is usually fixed torque on each of a shaft and driven by the respective shaft, wherein the two shafts are coupled together by a arranged in a transmission housing gearbox

The known rotary lobe pumps are self-priming and dry running insensitive. The principle of operation is based on the fact that the rotary pump operating as a displacement pump effects the fluid transport by means of the two rotary pistons on one wall of the housing along the pump inlet to the pump outlet, while the two rotary pistons in the middle of the housing are in fluid-tight contact with each other and rotate counter-clockwise in one another.

The invention is based on the recognition that housing known rotary lobe pumps are made either in block construction and consist of a solid housing block or are composed of several housing shells.

In this case, the invention has recognized that made of solid blocks pump housing in production are very expensive, since the complicated internal geometry of the pump chamber must be machined usually made with high surface quality. Massive block housings in rotary lobe pumps have the further disadvantage that on the one hand they have a very high component weight and on the other hand they have to be completely replaced even if only a portion of the housing is worn. Remedy can only be created in these rotary lobe pumps with these types of housing that additional cup-shaped inserts are provided, which preferably wear out and are interchangeable if necessary.

On the other hand, according to the invention, rotary lobe pumps which have a housing composed of housing shells pump housing, in contrast, have the advantage that only those parts of the pump housing must be replaced, which are maintenance or replacement, while other, less stressed housing parts need not be replaced , The pump housing of this type are fluid-tightly closed by means of clamping means by the housing half shells against each other or against other housing parts are braced. In addition, the interfaces of the housing half-shells are sealed against fluid entry and / or exit, for example by means of paper seals.

Furthermore, it is recognized according to the invention that pump housings which have two housing half-shells open up the further theoretical manufacturing advantage that they can be produced by manufacturing a circular housing and subsequent separation of this housing into two housing half-shells. In this way, although the machining of the inner surfaces of the housing half-shells is simplified, since a circular inner surface can be edited here. However, it has been shown that after separating the machined component in two housing half-shells by the effect of residual stresses the desired accuracy and geometric precision of the housing halves is missed. This makes a costly reworking necessary or requires a corresponding bracing of the housing halves during assembly. The theoretical manufacturing advantage is thus faced with another disadvantage, so that split housing are disadvantageous in rotary lobe pumps.

Consequently, the present invention has the object to provide a rotary piston pump, which has a comparison with these disadvantages both in manufacturing and in the dimensionally improved pump housing.

The invention was also based on the object of specifying an improved housing for a rotary lobe pump.

The invention solves the underlying object in a rotary piston pump of the type mentioned by the pump housing has two opposite housing half-shells, which seal the pump housing fluid-tight and the housing half-shells are double-walled. The invention makes use of the fact that the stability of the housing as a whole and the housing half shells themselves is significantly increased by the housing is double-walled, without the modular concept of the half-shell construction must be abandoned. Due to the double-walled design of the housing half-shells, there are a number of surprising advantages. The entire pump housing has a reduced susceptibility to vibration. The stability of the rotary lobe pump under the influence of pressure and under the influence of external, for example, induced by pipe tension forces is increased. Due to the increased stability associated with the double wall, the dimensional stability of the housing half-shells is increased, which is reflected advantageously in an improved manufacturing precision. The improved manufacturing precision allows mounting of the pump housing free of paper or similar seals. Preferably, the housing half-shells are free of sealants directly to each other or to one or more other housing components in abutment and fluid-tight clamped. Optionally, the pump housing has a film or foil-like sealant between the housing parts. In any case, the manufacturing tolerances of the assembled pump housing on the whole due to the avoidance of paper seals or comparable, still necessary in the known rotary lobes seals are further improved.

With respect to each other in relation to the housing half-shells, it is to be understood here that the housing half-shells are in the sense of a mirror or mirror in relation to a plane through which the longitudinal axis of the rotary-piston pump runs and which lies in particular perpendicular to a plane enclosing the axes of rotation of the rotary piston Opposite line symmetry.

With the rotary piston pump according to the invention an advantageous manufacturing method is opened by first cast the housing half-shells as a contiguous, circular in cross-section housing and the inner surface is machined in a continuous cut, for example on a lathe. Subsequently, this double-walled housing can be separated by separation into two housing half-shells, whereby the known problems of distortion and residual stresses due to the higher rigidity of the housing are avoided. The geometry of the pumping space is then achieved, for example, by attaching the two housing halves to each side of an axial intermediate housing.

The invention is advantageously further developed in that a cavity is formed between an inner wall of the housing half-shell and an outer wall of the housing half-shell. The inner wall is formed spaced from the outer wall. As a result, vibrations are transmitted from the inner wall to a lesser extent to the outer wall. The torsional rigidity is increased. Furthermore, the cavity is preferably fillable with a material for acoustic damping.

Preferably, one or more struts are formed in the cavity of the housing half shell, which extend from the inner wall to the outer wall. By means of the struts, the rigidity of the housing half shell and thus of the pump housing and as a result of the entire rotary pump is further increased. The struts are preferably adapted to support the inner wall relative to the outer wall.

According to a further preferred embodiment of the invention, one or more ribs are formed in the cavity of the housing half shell, which extend from the inner wall to the outer wall. By means of the ribs, the rigidity of the housing half-shell and thus of the pump housing and as a result of the entire rotary piston pump is also further increased. The ribs are preferably adapted to support the inner wall relative to the outer wall. In a preferred embodiment, both ribs and webs between the inner wall and the outside are provided for their mutual support.

In yet an advantageous development of the invention, the outer wall of the housing half-shell on a through hole, which is designed to receive or release a coolant in or out of the cavity between the inner wall and the outer wall. Alternatively, a heated fluid can also be supplied and / or removed in order to obtain a temperature in the interior of the pump housing that is favorable for the respective pumping operation. Preferably, a cooling system is communicably connectable or connected to the rotary piston pump or to one or both housing half-shells, which has means for regulating the temperature of the cooling or heating fluid. In a preferred embodiment, each housing half-shell ribs and / or webs between the inner wall and the outer wall and has a through-flow of cooling or heating means interior, so that the webs and / or ribs are formed to the fluid line in the interior of the cavity. Individual areas can be preferably flow around with the cooling or heating medium in the way.

The rotary piston pump according to the invention preferably has an intermediate housing. Preferably, the housing half-shells are fluid-tightly connected by means of the intermediate housing. In this embodiment, the pump housing preferably comprises two housing half-shells and the intermediate housing connecting the housing half shells. Preferably, the intermediate housing and the housing half shells each have correspondingly formed end faces, which can be brought into fluid-tight contact with the end faces of the respectively adjacent housing.

Preferably, the intermediate housing defines a distance between the two housing half-shells, and the distance between the two housing shells is adjustable depending on the wear. Preferably, a plurality of differently positioned fitting holes are provided, which are engageable in various configurations with fitting elements, in particular hollow-clamping pins or dowel screws, wherein the respective configuration of fitting elements for positioning the housing half-shells relative to the intermediate housing in each case to different configurations Distance is set up. As a result, a readjustment of said position is possible depending on the wear of the housing half shells. The housing half-shells preferably have an inner surface which cooperates in a substantially fluid-tight manner with the rotary piston arranged relative to the inner surface and rotatable relative to the inner surface to form one or more delivery cavities. The inner surface is exposed to wear, in particular during solid-state loading of the fluid to be delivered by the rotary pump, and explodes over time as the operation continues. By means of the adjustability according to the invention, the period of time until the necessary replacement of a housing half-shell is thus lengthened.

The intermediate housing preferably has exchangeable spacer elements. The spacer elements are preferably formed as spacers or flat body, which can be arranged between the intermediate housing and the housing half-shell to define the distance between the adjacent housing half-shells and / or in each case a housing half-shell and the intermediate housing. The spacers are preferably made with a narrow tolerance, so that the aforementioned distance in a range of less than 1 mm, more preferably less than 0.3 mm is adjustable.

In a preferred rotary piston pump, the intermediate housing is double-walled. Advantageously, the intermediate housing has an inner wall and an outer wall, wherein a cavity is formed between the inner wall and the outer wall of the intermediate housing. Particularly preferably, the cavities of the housing half-shells and the intermediate housing are communicatively connected to each other. The advantages with respect to the formed in the housing half-shell cavity also takes the cavity provided with intermediate housing to himself. In particular, the intermediate housing is thus provided with a means for acoustic damping, and / or with cooling and / or heating means fillable or flow around.

Furthermore, according to a preferred embodiment, it is provided that the mutually opposite housing half-shells and the intermediate housing axial end faces which are connected by threaded rods, in particular braced, wherein the threaded rods preferably inside a cavity in the housing half shell or the intermediate housing, as explained above , are arranged. The internal arrangement of the threaded rods or equivalent clamping means offers several advantages. First, the threaded rods are better protected against corrosion and mechanical impact and manufacturing and maintenance is facilitated in terms of coating and cleaning. Furthermore, the internal arrangement allows the formation of a symmetrical end face of the intermediate housing and / or the respective housing half-shell. Preferably, the threaded rods within the cavity of the housing half-shell and / or the intermediate housing can be arranged so that a force applied by the threaded rods clamping force is substantially uniformly transmitted to the inner wall and the outer wall. There is preferably no bending moment resulting therefrom.

Still further, it is preferred that the two opposed housing half shells form a first housing half-shell pair and that there is at least one further, second pair of each two opposite housing half shells, which is thus arranged axially adjacent to the first pair of housing halves, a housing half shell of the first pair has an axial end face and this axial end face is connected to an axial end face of a housing half shell of the second pair and the corresponding other housing half shell of the first pair has an axial end face and has this axial end face axial end face of the corresponding other housing half shell of the second pair is connected. With this embodiment, it is possible to produce a series of rotary lobe pumps efficiently and of high quality by the pump volume is increased by appropriate axial juxtaposition of several housing half-shell pairs. The distortion accuracy and manufacturing precision of the double-walled housing half-shells allows an immediate axial juxtaposition of two or more housing halves and thus the production of a rotary piston pump having an increased pump volume (eg, by a factor of 1.5 or 2 or 3) with respect to the rotary lobe pump Housing shell pair has.

According to a further preferred embodiment, spacer elements are provided for the axial extension of the intermediate housing and / or spacer elements for the axial extension of the housing half-shells. These spacer elements preferably correspond to the axial cross section of the housing halves or of the intermediate housing. They have a defined thickness and extend according to the principle of shims the housing halves or the intermediate housing in the axial direction to compensate for manufacturing tolerances or to meet application-specific requirements and to allow the use of standardized manufactured housing halves or the intermediate housing. The spacer elements can be used in the same way for mounting and adjustment in rotary lobe pumps with a pair of housing half shells as well as in rotary lobe pumps with two or more pairs of housing half shells.

The invention solves their underlying task in a housing half shell of the type mentioned for a rotary piston pump for conveying a fluid medium containing solids by the housing half-shell is double-walled.

Further advantageous embodiments of the housing half shell arise from the above discussions on the preferred embodiments of the rotary piston pump according to the invention. Reference is made to these statements.

The invention further relates to a method for producing housing shells for a rotary pump for conveying a fluid medium containing solids.

To a housing half-shell in the context of the invention for a corresponding rotary pump, a high requirement is placed on the cylindricity of the inner surface with respect to an inner surface of the housing half-shell, after this inner surface is part of the delivery cavities of a rotary piston pump.

Known methods for producing such housing half-shells provide the casting of two housing shells, which are mounted next to each other. After installation, a cylindrical inner surface is formed in half by half in the housing half shells by means of boring. An exact positioning and later repositioning of the housing half shells to each other make the manufacturer before production engineering challenges, which means a high time and cost.

The invention was therefore also the object of providing an improved manufacturing method for an inventively improved housing half-shell to obtain an improved rotary lobe pump.

• – Bereitstellen oder Herstellen einer Gussform für einen Gehäuse-Rohling, wobei die Gussform als ein Negativ eines herzustellenden Gehäuse-Rohlings ausgebildet ist und dazu eingerichtet ist, den Gehäuse-Rohling einstückig derart herzustellen, dass dieser zwei Halbschalen-Abschnitte aufweist und doppelwandig ausgebildet ist,
• – Herstellen des Gehäuse-Rohlings mittels Einbringen von fließfähigem Guss-Material in die Gussform und Aushärten des fließfähigen Gussmaterials,
• – Bearbeiten des Gehäuse-Rohlings, so dass eine zylindrische Innenfläche des Gehäuse-Rohlings resultiert, und
• – Trennen der Halbschalen-Abschnitte des Gehäuse-Rohlings im Anschluss an das Bearbeiten des Gehäuse-Rohlings, so dass zwei Gehäuse-Halbschalen resultieren, die jeweils doppelwandig ausgebildet sind.

The invention solves its underlying object in a method of the aforementioned type with the steps:

• Providing or producing a casting mold for a housing blank, wherein the casting mold is formed as a negative of a housing blank to be produced and is adapted to produce the housing blank in one piece such that it has two half-shell sections and is double-walled,
• Preparing the housing blank by introducing flowable cast material into the mold and curing the flowable cast material,
• - Processing the housing blank so that a cylindrical inner surface of the housing blank results, and
• - Separate the half-shell sections of the housing blank after the processing of the housing blank, so that two housing half-shells result, which are each formed double-walled.

The method according to the invention makes use of the knowledge that the cylindricity of the inner surface of each housing half shell can be produced most reliably if the inner surface is provided in a one-piece housing blank. However, the known methods did not allow this, as occurred in the known casting process with known molds gefügebedingte and form-related stresses in the housing blank, which had an unacceptably high Maßverzug result when, after casting and processing of the housing blank, For example, by turning the inner surface, only the separation into two half-shells made. The housing blank sprang up to a certain extent. The inventive method starts here by a Mold is provided for a housing blank, which is formed as a negative of a housing blank to be manufactured and is adapted to the housing blank in one piece to produce such that it has two half-shell sections and is double-walled. The double-walled design of the half-shell sections by means of the correspondingly configured casting mold drastically reduces the dimensional distortion in a subsequent separation of the half-shell sections. Thus, it is possible to make the machining of the still one-piece housing blank, so that a cylindrical inner surface of the housing blank results, and only then make the separation of the half-shell portions of the housing blank. The inventive method high-dimensional housing half-shells are obtained with a significantly reduced compared to the known methods manufacturing cost. In addition, a housing half shell produced by the method according to the invention has various advantages, which have already been explained above, and to which reference is hereby made.

The method is further developed in that a cavity is formed between an inner wall of the housing blank and an outer wall of the housing blank. The cavity is particularly preferably formed by means of the casting mold. Alternatively, the cavity is made following the curing of the housing blank by means of material removal.

In a further preferred embodiment of the method, the housing blank is produced such that in the cavity of the housing blank one or more struts and / or ribs are formed, which extend from the inner wall to the outer wall. The webs and / or ribs are particularly preferably formed by means of the casting mold. Alternatively, the ribs and / or webs are introduced into the cavity following the hardening of the housing blank, for example by means of screwing, pinning, riveting, welding, soldering or gluing.

The separation of the half-shell sections of the housing blank is preferably carried out by machining, for example by means of sawing. By sawing and, where appropriate, a post-processing of the cut edges, for example by means of milling, a high surface quality of the cut edge is achieved.

Alternatively, the separation of the half-shell sections of the housing blank takes place by means of non-cutting machining, for example by means of water jet cutting or laser cutting. Water jet cutting is advantageous because the thermal influence of the cutting zone is low.

The machining of the housing blank, so that a cylindrical inner surface of the housing blank results, is preferably carried out by machining, preferably by means of rotation.

• – thermische Nachbehandlung des Gehäuse-Rohlings im Anschluss an das Aushärten des fließfähigen Gussmaterials, so dass Eigenspannungen in dem Gehäuse-Rohling reduziert werden. Dies verbessert die Maßhaltigkeit der Gehäuse-Halbschalen noch weiter.

The method according to the invention in a preferred embodiment further comprises the step:

• - Thermal treatment of the housing blank after curing of the flowable cast material, so that residual stresses in the housing blank are reduced. This further improves the dimensional accuracy of the housing half-shells.

The invention will be explained in more detail below with reference to preferred embodiments and with reference to the accompanying figures. Hereby shows:

1 a schematic cross-sectional view of a pump housing of a rotary piston pump;

2 a side view of a housing half-shell according to the present invention;

3 another side view of the housing half shell 2 ;

4 a cross-sectional view of the housing half-shell of 2 and 3 ; and

5 a spatial sectional view of the housing half-shell of 2 to 4 ;

In 1 First is the basic structure of a pump housing 1 a rotary pump according to the present invention. The pump housing 1 has two housing half shells 3 on. The housing half shells 3 are at a distance 5 arranged from each other. The distance 5 preferably corresponds to the center distance of two drive axles 13 , The drive axles 13 are assigned to a (not shown) gear, parallel in a plane 11 arranged and each by means of a feather key 9 torque-resistant, each with a rotary piston 7 connected.

The housing half shells 3 have side faces facing each other 15 on. The side surfaces 15 are designed to be fluid-tightly connected to an intermediate housing (not shown). The intermediate housing defines the preferably adjustable distance 5 between the housing half shells 3 ,

The housing half-shells each have an inner surface 19 on. The inner surface 19 each preferably has a semi-cylindrical contour. The in 1 left rotary pistons 7 forms in the position shown a Förderkavität 17 between itself and the inner surface 19 the associated housing half-shell 3 out.

The double-walled construction of the housing half-shells 3 is shown in more detail in the following figures.

2 and 3 each show a projection of a side view of a housing half-shell 3 according to the present invention. The housing half shell 3 has an end face 21 on. The face 21 is preferably planar and engageable with a correspondingly formed surface of a lid (not shown). The housing half shell 3 points between an outer surface 23 and the inner surface 19 in the frontal area 21 a number of through holes 25 on which are from the frontal area 21 into a cavity (see 4 ). The through holes 25 are along the perimeter of the face 21 arranged distributed. The substantially cylindrical outer surface 23 has along its circumference a number of flat surface sections formed 27 on. The surface sections 27 are designed to radial through holes 29 To record passport holes or the like.

4 and Fig. 1 each show sectional views of a housing half-shell according to the present invention. 4 shows a cross-sectional view through a housing half-shell according to a preferred embodiment of the present invention, while 5 a spatial representation of a quarter section of the housing half-shell according to the invention. With respect to the same reference numerals to the above explanations to the 1 to 3 directed. The housing half shell 3 has proven 4 an inner wall 31 and an outer wall 33 on. Between the inner wall 31 and the outer wall is a cavity 32 educated. The housing half-shell is double-walled. Between the inner wall 31 and the outer wall 33 is a number of footbridges 35 educated. The bridges 35 each extend between the inner wall 31 and the outer wall 33 , The bridges 35 are decorated to the inner wall 31 and the outer wall 33 to support one another. The illustrated through hole 29 extends from one of the newly formed sections 27 the outer surface 23 through the outer wall 33 through into the cavity 32 , The through hole 29 is optionally formed as an inlet or outlet and for receiving and / or output of a cooling and / or heating means and / or arranged to receive filler material such as Dammstoff against vibration and / or sound, with which the cavity 32 is fillable. Next optional are sensors or data or power lines by means of the through hole 29 in the cavity 32 deployable. A housing half shell 3 preferably has a plurality of through holes 29 on.

The outer wall 33 and the inner wall 31 are in a side section 37 connected to each other and preferably merge into one another in one piece.

The side surfaces 15 are formed parallel to each other. Which is between the side surfaces 15 inside extending inner surface 19 is semi-cylindrical and spans an angle of 180 °.

In 5 is shown that in the area of the through hole 29 a reinforcement 39 in the cavity 32 is trained. The reinforcement 39 supports the inner wall 31 against the outer wall 33 in the area of the through hole 29 continue down.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007054544 A1 [0003]
• EP 1624189 B1 [0003]
• DE 102005017575 A1 [0003]
• WO 2007/026109 A1 [0003]

Claims (12)

Rotary piston pump for conveying a fluid medium containing solids, with an inlet and an outlet respectively for the medium to be delivered, with a pump housing ( 1 ) and two in the pump housing ( 1 ) arranged rotary pistons ( 7 ) with interlocking rotary lobes, characterized in that the pump housing ( 1 ) two opposing housing shells ( 3 ), which the pump housing ( 1 ) fluid-tight and that the housing half-shells ( 3 ) are double-walled. Rotary pump according to claim 1, characterized in that between an inner wall ( 31 ) of the housing half-shell ( 3 ) and an outer wall ( 33 ) of the housing half-shell ( 3 ) a cavity ( 32 ) is trained. Rotary pump according to claim 2, characterized in that in the cavity ( 32 ) of the housing half-shell ( 3 ) one or more struts ( 35 ) are formed, which from the inner wall ( 31 ) to the outer wall ( 33 ). Rotary pump according to claim 2 or 3, characterized in that in the cavity ( 32 ) of the housing half-shell ( 3 ) one or more ribs are formed which extend from the inner wall ( 31 ) to the outer wall ( 33 ). Rotary pump according to one of the preceding claims 2-4, characterized in that the outer wall ( 33 ) of the housing half-shell ( 3 ) a through hole ( 29 ) for receiving or discharging a coolant into or out of the cavity ( 32 ) between the inner wall ( 31 ) and the outer wall ( 33 ) is trained. Rotary piston pump according to one of the preceding claims, characterized in that the housing half shells ( 3 ) are fluid-tightly connected by means of an intermediate housing. Rotary pump according to claim 6, characterized in that the intermediate housing a distance ( 5 ) between the two opposite housing half shells ( 3 ), and that the distance ( 5 ) between these two housing shells ( 5 ) is dependent on wear adjustable. Rotary pump according to claim 6 or 7, characterized in that the intermediate housing has an inner wall and an outer wall, and that between the inner wall and the outer wall of the intermediate housing, a cavity is formed. Rotary pump according to one of the preceding claims, characterized in that the mutually opposite housing half-shells ( 3 ) and the intermediate housing axial end faces ( 21 ), which are connected by means of threaded rods, in particular braced, wherein the threaded rods are preferably arranged inside in a cavity according to claim 2 or 7. Rotary piston pump according to one of the preceding claims, characterized in that the two opposite housing half-shells ( 3 ) form a first pair of housing half-shells and characterized by at least one further, second pair of each two opposite housing half shells, which is arranged axially adjacent to the first pair of housing half shells such that - a housing half shell of the first pair has an axial end face and these axial End face is connected to an axial end face of a housing half shell of the second pair and - correspondingly different housing half shell of the first pair has an axial end face and this axial end face is connected to an axial end face of the corresponding other housing half shell of the second pair. Rotary pump according to one of the preceding claims, characterized by exchangeable spacer elements for the axial extension of the intermediate housing and / or characterized by exchangeable spacer elements for the axial extension of the housing half-shells. Housing half shell ( 3 ) for a rotary pump for conveying a solids-containing fluid medium according to one of claims 1 to 11, characterized in that the housing half-shell ( 3 ) is double-walled.

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